Diabetes mellitus is a disease of mammals which is characterized by an intolerance to carbohydrates and an inadequate production and secretion of insulin by the .beta.-cells in the islets of Langerhans. The disease is often associated with vascular degeneration, especially atherosclerosis. Hypoglycemic agents which are effective in lowering blood sugars may be used in the treatment of certain types of diabetes. U.S. Pat. No. 3,983,164 describes a group of benzoic acid derivatives which have demonstrated hypoglycemic activity.